Various medical procedures (e.g., intubation procedures) involve a distal end of a tube being inserted into a specific area of a patient and then using the tube for injecting material into the patient and/or for removing material from the patient. However, safely securing such a tube at a particular position within the patient during use has heretofore been infeasible. Moreover, safely preventing certain material from passing along the external surface of such a tube during use has heretofore been infeasible.